蓝莓茎段丛生芽诱导最适培养基的筛选研究

利用蓝莓的茎段为外植体,培养在添加不同浓度的6-BA和ZT的改良WPM培养基上,研究蓝莓离体繁殖影响因素,筛选蓝莓茎段诱导丛生芽的最佳培养基。结果表明:在WPM(改良)+6-BA 1.0mg/L+ZT 1.0mg/L的培养基上诱导的丛生芽数量最多,长势最好。     

乌拉尔甘草离体再生与遗传转化技术的研究

研究乌拉尔甘草离体再生受体系统和遗传转化技术方法,为甘草基因工程育种提供前期实验基础。以乌拉尔甘草茎段为外植体,试验筛选最适不定芽分化培养基和增殖壮苗培养基; 以乌拉尔甘草茎段为受体,利用农杆菌介导法对乌拉尔甘草进行GUS和GFP基因的遗传转化研究。结果表明,以乌拉尔甘草去腋芽茎段为外植体,其不定芽最适分化和增殖培养基配方为MS+0.1 mg/L TDZ+0.1 mg/L 6BA+0.1 mg/L IBA,不定芽分化率达38.8%,增殖倍数3.67,适宜的壮苗培养基为MS+0.5 mg/L NAA。与去腋芽茎段相比,带腋芽茎段的不定芽分化率达100%,能够在含抗生素的选择培养基MS+0.1 mg/L TDZ+0.1 mg/L 6BA+0.1 mg/L IBA+50 mg/L Kan+250 mg/L Car上存活,确定为最适转化受体;带腋芽茎段在分化培养基上预培养7 d后,经OD₆₀₀=0.6的菌液侵染10 min,共培养3 d,在选择培养基上培养20 d,其不定芽分化率为43.75%,经GFP荧光检测可得到78.88%的GFP基因瞬时表达率;随机选取5株再生转化植株,经PCR检测,均有GFP和GUS基因的目的条带,GFP基因表达较强烈,初步获得了5个株系的阳性转化植株。     

兔眼蓝莓‘园蓝’离体培养增殖技术研究

本试验以兔眼蓝莓主栽品种‘园蓝’为试材,研究其离体培养增殖技术。基本培养基为WPM培养基,添加蔗糖20g/L,琼脂10g/L,pH为5.2。实验总体分为两个过程：第一步,在基本培养基中加入ZT (2mg/L, 4mg/L, 6mg/L)或2ip (2mg/L, 5mg/L, 10mg/L),共6个处理,培养60d后,观察记录蓝莓腋芽萌发情况,WPM ZT 4mg/L更有利于腋芽萌发,各处理中腋芽萌发后生长速度都很慢;第二步,在基本培养基中加入4mg/L的ZT及IAA（0.1mg/L, 0.2mg/L）或IBA（0.1mg/L, 0.2mg/L）,共4个处理,培养60d后进行数据统计,发现最佳处理为WPM ZT 4mg/L IBA 0.2 mg/L,并且芽子长势较好。因此,兔眼蓝莓‘园蓝’腋芽诱导和生长的最佳培养基为WPM ZT 4mg/L IBA 0.2 mg/L。     

地被菊‘紫妍’和‘纽9722’的再生体系建立

本研究以地被菊(Chrysanthemum morifolium)两个品种‘紫妍’和‘纽9722’带腋芽的无菌茎段为外植体,在基本培养基中添加不同浓度的6-BA和NAA诱导叶片分化、茎段增殖以及继代生根,进行两个品种的再生体系建立。结果表明,利用2%NaClO对‘紫妍’和‘纽9722’适宜消毒时间分别为6、8min;诱导‘紫妍’叶片不定芽再生的最适培养基是MS+6-BA 2.0mg·L-1+NAA 1.0mg·L-1,愈伤组织诱导率为100%,分化率为92.22%,出芽数为7.60;‘纽9722’叶片不定芽再生的最适培养基是MS+6-BA 2.0mg·L-1+NAA 0.5mg·L-1,愈伤组织诱导率为100%,但分化率仅为45.59%;‘纽9722’茎段增殖的最适培养基是MS+6-BA 2.0 mg·L-1+NAA 0.5mg·L-1,增殖系数高达10.05;‘紫妍’生根的最适培养基是1/2 MS+NAA 0.2 mg·L-1,生根率为100%,生根系数为15.50;‘纽9722’生根的最适培养基为1/2 MS+NAA 0.3mg·L-1,生根率为100%,生根系数为14.87,移栽成活率均为100%。     

唐古特白刺组织培养及其培养基筛选研究

本试验选用唐古特白刺幼嫩茎段和叶片作为材料,研究白刺不同外植体的离体培养技术及其适宜的培养基。结果表明,白刺带芽嫩茎是诱导丛生芽的良好外植体,恒温20℃以下,可有效降低白刺丛生芽初代培养污染严重的程度;叶片是诱导愈伤组织的良好外植体,且低浓度生长素2,4-D培养基较高浓度培养基形成的白刺愈伤组织致密,也不易褐化。白刺的最适增殖、壮芽培养基为MS+6-BA 2 mg/L+NAA 1.00 mg/L,而且是以腋芽形成丛生芽的方式进行增殖的;最适生根培养基是1/2 MS+KT 1 mg/L+IBA 0.5 mg/L;形成愈伤组织较好的培养基是MS+2,4-D 0.5～1.0 mg/L。     

地被菊‘雪公主’的组织培养和快速繁殖

以地被菊‘雪公主’（Chrysanthemum grandiflorum cv.White Snow）带腋芽的茎段为外植体,通过消毒得到无菌材料。以MS为基本培养基,通过增加不同浓度的激素进行组织培养快速繁殖技术的研究。结果表明,诱导叶片不定芽的最适培养基为MS+1.0 mg·L-16 BA+0.7 mg·L-1NAA,诱导率达100％,分化率达63.3％;茎段增殖的最适培养基为MS+0.3 mg·L-16 BA+0.2 mg·L-1NAA,平均增殖系数为6.73;继代培养为MS培养基;生根培养基为1/2MS+0.5 mg·L-1NAA培养基,生根率达100％,平均生根系数为15.80;移栽后生长良好,成活率达100％。     

无籽沙糖桔高效离体再生体系的建立

本研究以无籽沙糖桔异交种子(无籽沙糖桔×有籽沙糖桔) 的实生苗上胚轴为材料,研究了不同种类的激素及组合对无籽沙糖桔离体再生的影响,建立了高效的无籽沙糖桔离体再生体系。结果表明：ZT和TDZ不利于无籽沙糖桔不定芽的诱导;在一定浓度范围内,随着6-BA浓度的增加,不定芽诱导率和平均每个外植体不定芽数显著增加。当以MT为基本培养基、6-BA浓度为0.25 mg/L时,不定芽诱导率和平均每个外植体不定芽数最高,分别为88.5%和2.7个/外植体;当不同浓度的6-BA与不同浓度的IBA组合时,以6-BA 0.25 mg/L + IBA0.25 mg/L为最佳激素组合,不定芽诱导率达95.2%,平均每个外植体萌芽数为3.6个;再生的不定芽在附加IBA 1.0 mg/L的MT 培养基中生根并再生植株。     

露地菊‘纽9717’的茎叶离体快繁体系

以露地菊‘纽9717’(Chrysanthemum×grandiflora ‘niu9717’)无菌苗为试验材料, 进行茎段(含腋芽)离体快繁体系和离体叶片不定芽再生体系的研究。结果表明, 最佳茎段增殖培养基为MS+6-BA 0.3 g·L-1+KT 0.5 g·L-1+NAA 0.5 g·L-1, 平均增殖系数为3.2;最佳叶片离体再生培养基为MS+6-BA 2.0 g·L-1+NAA 0.5 g·L-1, 6-BA与NAA组合更有利于愈伤组织分化, 愈伤组织诱导率为100%, 愈伤组织分化率为92.3%, 繁殖系数为8.9, 其中分裂素KT及TDZ不利于愈伤组织诱导及不定芽分化, 生长素2, 4-D能有效诱导愈伤组织, 但抑制不定芽分化;最佳生根培养基为1/2MS+IBA 0.05 g·L-1, 生根率达100%, 平均生根数为12.08, 平均根长1.5 cm, 移栽成活率为100%, 高浓度生长素能诱导根形成但抑制根的伸长。     

软枣猕猴桃‘奇异莓6号’离体再生技术

以软枣猕猴桃无芽茎段为外植体进行离体培养,具有成本低、取材方便、材料充足等优点,但以往的研究表明无芽茎段诱导再生率低。本试验以‘奇异莓6号’软枣猕猴桃无芽茎段为外植体,探究不同植物生长调节剂、光照强度、温度、苗龄对不定芽诱导的影响。结果表明：最佳外植体为苗龄30d的无芽茎段,在光照12h/d(光照强度50LX)、室温20℃下,不定芽诱导的最适培养基为MS+2mg/L ZT,不定芽以间接途径发生,培养40d无芽茎段两端开始形成淡绿色愈伤组织,培养45d愈伤组织表面出现红色小点,开始形成不定芽,培养55d愈伤组织诱导率、愈伤组织分化率及不定芽数均到最大,分别为100%、100%及18.87个/块。待苗长至3cm左右时转到MS+0.4mg/L ^IBA中进行生根培养,培养30d生根率可达100%、根数为8.53/株、根长1.68cm、根粗0.14cm。     

香蓼带芽茎段的组织培养和快速繁殖

以香蓼(Polygonum viscosum)带芽茎段为外植体, MS为基本培养基, 研究了不同浓度的激素对腋芽诱导、腋芽增殖和生根的影响, 从而初步建立了香蓼组织培养快速繁殖体系。结果表明, 诱导腋芽的最适宜培养基为MS+2.0 mg·L^-16-BA+0.1 mg·L^-1NAA, 诱导率为88.89%;腋芽增殖的最适培养基为MS+2.0 mg·L^-1 6-BA+0.3 mg·L^-1NAA+0.5 mg·L^-1 KT, 增殖倍数为5.17;生根的最适培养基为1/2 MS+0.7 mg·L^-1NAA, 生根率高达98.89%, 移栽后植株生长良好, 成活率较高, 达93.33%。该结果为香蓼快繁和基因工程研究提供了新的数据支持。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in